Part I took place in 2007 and children 15-16 and 16-17 years across Cyprus were invited to participate. The targeted population were 19849 children that participated in an earlier study in years 2001-3 and had anthropometric measurements, assessment of cardio-respiratory fitness and serum lipids taken at that time. The subjects of the second part of the study were selected from the 5384 subjects that had participated in the first part and had matched data on current and past BMI. We targeted subjects for part two of the study with the following criteria:1. Current Wheezers: All active asthmatics across all BMI subgroups. Definition of Current Wheezer: Positive answer to the question in ISAAC questionnaire: "Have you had wheezing in the past 12 months?" 2. Never Wheezers: 700 controls selected in a random way across all BMI groups. Definition of Never Wheezer: Negative answers to both of the following two questions: "Have you ever had wheezing?" and "Have you ever had asthma?"